Student and teacher relationship is very vital to students academic performance and social developments at all levels of education, i mean from creche to post graduates studies. most students need help, someone who can pep talk talk them in order to improve their confidence level, that is an ideal teacher comes in.
Definition of a teacher: A teacher is a person who helps others to acquire knowledge, competences or values. Informally the role of teacher may be taken on by anyone. Wikipedia
I know you will agree with me teaching is one of those profession that is least appreciated in our society but thank goodness the tide is changing with the new generation schools.
Definition of a relationship: An interpersonal relationship is a strong, deep, or close association or acquaintance between two or more people that may range in duration from brief to enduring. This association may be based on inference, love, solidarity, regular business interactions, or some other type of social commitment.
Therefore, student and teacher relationship is a bond, acquaintance, solidarity and commitment that a teacher shows toward his/her students with the sole aim of improving the competences, academic and moral values of the students.
What are the importance of teacher student relationship
It improve students confidence: there is surge of confidence in you when you know your teacher has an interest you. have you ever wonder why children borne in the 21st century are pretty sharp and confident, the reason behind this is because most of these children attend these generation schools from age zero, and from there they build on. but if you compare this with the contemporary schools where teacher students relationship is non existent other than a teacher go to class, teach and get out of the class.
It makes learning fun: Teacher student relationship makes learning fun and effortless, this does improve the academic performance of the student as learning becomes an habit and you will agree with me that when learning becomes an habit, the sky is just the starting point on how far the student can go.
Read more about this on the link below
https://www.studentssupport.com.ng/2018/08/teacher-and-student-relationship.html?m=1

Teacher student relationship ended at primary and secondary schools in Nigeria while at the university you this in most private universities.